Red-footed Cannibals

One hates to dispute with the Bard. He is dead, after all, and cannot defend himself, but I’m not sure he’s right about names. In my experience our words often bias our senses. If it were known as the Tudor Stinkthorn, I suspect that a Rose might not smell as sweet.

Which brings me to flies.

Red-footed Cannibal, Promachus rufipes) mating pair.

I recently came across two mating predatory flies. They were flying in tandem—one facing north and the other facing south. Sadly, I did not get a picture of that; however, I did manage a couple of shots of them after they landed in a weed.

And they got me thinking about names.

These are Robber Flies, members of a common enough family of aggressive predators in the family Asilidae, of which there are more than a hundred species in the eastern United States.[1]

This fly is in the genus Promachus, which includes some twelve species in the eastern United States.[2] Specifically, if my ID is correct, this is a Red-footed Cannibal (Promachus rufipes). Now there is an evocative name. I wish I knew its provenance.

I get the red-footed part, although the feet are more a burnt orange (I have to admit, Burnt-orange-footed Cannibal is not as catchy). How did they earn the unhappy reputation for eating their own kind? Did some entomologist actually witness such a repellent repast?[3]

Note the “red” feet. They do not seem all that red to me.

In addition, under the “Info” tab, BugGuide tells us that this fly is also called a “Bee Panther.” That is informative, but not too much. All of the larger Robber Flies are known as bee killers. They grab their prey in those spiny legs, stab it with their proboscis, and inject a paralytic that renders the prey both motionless and digestible. They will take quite large bees, and in fact, two different species, including the Red-footed Cannibal, have been reported to attack hummingbirds.[4]

Finally, there is the Latin name, Promachus rufipes, which translates roughly to the red-footed champion. I don’t get that at all.